腐殖酸钾对红壤镉的稳定作用与机制  

Stabilizing effect and mechanism of potassium humate on cadmium in red soil

作　　者：潘少兵 张雪晴 谢颖 代二海 王国鑫 胡程凯 彭可睿 林雨欣 陶炳娇 PAN Shaobing;ZHANG Xueqing;XIE Ying;DAI Erhai;WANG Guoxin;HU Chengkai;PENG Kerui;LIN Yuxin;TAO Bingjiao(College of Resources and Environment,Anqing Normal University,Anqing,Anhui 246133,China;Anhui Province Key Laboratory of Smart Monitoring of Cultivated Land Quality and Soil Fertility Improvement,Anqing,Anhui 246133,China;College of Metallurgy,Northeastern University,Shenyang,Liaoning 110819,China;College of Animal Science and Technology,Anhui Agricultural University,Hefei,Anhui 230036,China)

机构地区：[1]安庆师范大学资源环境学院,安徽安庆246133 [2]耕地质量智慧监测与地力提升安徽省重点实验室,安徽安庆246133 [3]东北大学冶金学院,辽宁沈阳110819 [4]安徽农业大学动物科技学院,安徽合肥230036

出　　处：《湖南农业大学学报(自然科学版)》2025年第2期60-67,共8页Journal of Hunan Agricultural University(Natural Sciences)

基　　金：安徽省高校自然科学重点项目(2024AH051087);安徽省教育厅质量工程教研项目(2023jyxm0482)。

摘　　要：以南方不同p H红壤为研究土壤,以不同添加量(0.0%、0.2%、0.4%、0.6%、0.8%)的腐殖酸钾为钝化剂,进行旱稻盆栽试验,原位获取土壤溶液并采用连续提取的方法研究土壤和土壤溶液镉(Cd)形态变化,从而探究腐殖酸钾对不同酸度红壤Cd污染的稳定作用与机制。结果表明:添加腐殖酸钾后,未酸化和酸化土壤及土壤溶液的pH、土壤有机质质量分数和土壤溶液溶解性有机碳质量浓度均不同程度地升高,且升高幅度与其添加量成正比;与对照相比,酸化与未酸化土壤添加0.8%腐殖酸钾后,土壤交换态Cd质量摩尔浓度分别降低了30%和20%,碳酸盐结合态Cd质量摩尔浓度分别降低了21%和增加了3%,铁锰氧化物结合态Cd质量摩尔浓度分别增加了14%和39%,有机结合态Cd质量摩尔浓度分别增加了26%和320%,土壤溶液Cd2+浓度分别降低了89%和95%,Cd–OM占比分别增加了33个百分点和48个百分点,稻米Cd质量分数分别降低了39%和35%。由此可见,添加腐殖酸钾提高了土壤和土壤溶液的p H和有机质含量,导致土壤交换态Cd和碳酸盐结合态Cd向更稳定的铁锰氧化物结合态和有机结合态转化,并促进了土壤溶液有机结合态Cd的形成及土壤溶液Cd向有机结合态Cd等稳定态Cd转化,从而降低了土壤溶液中毒性Cd的浓度,最终降低了稻米中Cd质量分数。另外,腐殖酸钾因具有较强的酸中和能力,其在低pH的土壤中效果更好。A pot experiment was set up on using southern red soils of varying pH levels to cultivate upland rice with potassium humate as a passivator at fiveapplication rates(0.0%,0.2%,0.4%,0.6%,0.8%).Soil solution samplers were collected in situ using a soil solution sampler combined with sequential extraction methods,to study cadmium(Cd)speciation changes in both soil and soil solution.This approach was used to explore the stabilization effects and mechanisms of potassium humate on Cd-contaminated red soils with varying acidities.The results showed that after the application of potassium humate,the pH,soil organic matter mass fraction,and dissolved organic carbon mass concentration in the soil solution increased to varying degrees in both acidified and non-acidified soils,with the increase being proportional to the application rate.Compared with the control,after adding 0.8%potassium humate the exchangeable Cd molalities in acidified and non-acidified soils decreased by 30%and 20%,respectively;the carbonate-bound Cd molalities decreased by 21%in acidified soil but increased by 3%in non-acidified soil;the Fe-Mn oxide-bound Cd molalities increased by 14%and 39%,respectively;the organic-bound Cd molalities increased by 26%and 320%,respectively;the Cd2+concentrations in the soil solution decreased by 89%and 95%,respectively;the proportion of Cd-OM increased by 33-and 48-percentage points,respectively;while the Cd content in rice grains decreased by 39%and 35%,respectively.These findings indicated that the addition of potassium humate increased the pH and organic matter mass fractions in both soil and soil solution,promoting the transformation of exchangeable Cd and carbonate-bound Cd into more stable Fe-Mn oxide-bound and organic-bound fractions,and also facilitated the formation of organic-bound Cd in the soil solution and the conversion of soil solution Cd into stable forms such as organic-bound Cd,thereby reducing the concentration of toxic Cd in the soil solution and ultimately decreasing Cd accumulation in rice grains.A

关 键 词：腐殖酸钾 红壤 旱稻 土壤溶液 镉污染 镉形态 

分 类 号：S156.6[农业科学—土壤学] X53[农业科学—农业基础科学]